How can I check if input is a letter or character in Python?
Input should be amount of numbers user wants to check.
Then program should check if input given by user belongs to tribonacci sequence (0,1,2 are given in task) and in case user enter something different than integer, program should continue to run.
n = int(input("How many numbers do you want to check:"))
x = 0
def tribonnaci(n):
sequence = (0, 1, 2, 3)
a, b, c, d = sequence
while n > d:
d = a + b + c
a = b
b = c
c = d
return d
while x < n:
num = input("Number to check:")
if num == "":
print("FAIL. Give number:")
elif int(num) <= -1:
print(num+"\tFAIL. Number is minus")
elif int(num) == 0:
print(num+"\tYES")
elif int(num) == 1:
print(num+"\tYES")
elif int(num) == 2:
print(num+"\tYES")
else:
if tribonnaci(int(num)) == int(num):
print(num+"\tYES")
else:
print(num+"\tNO")
x = x + 1
解决方案
You can use num.isnumeric() function that will return You "True" if input is number and "False" if input is not number.
>>> x = raw_input()
12345
>>> x.isdigit()
True
You can also use try/catch:
try:
val = int(num)
except ValueError:
print("Not an int!")